FIG 6.

Modeling the CcsBA heme binding domains. The CcsBA model generated as described for Fig. 2 was used to model heme into the internal and external heme binding domains using experimentally determined constraints. CcsB is red, and CcsA is blue. (A) Heme (green) in the internal heme binding domain, liganded by TM-His1 and TM-His2 (yellow). (B) Heme in both the internal and external heme binding domains. The external heme binding domain is magnified to show heme (yellow) in the WWD domain (magenta) with conserved Trp labeled and liganded P-His1 and P-His2 (green). (C) Top view of heme in both the internal and external domains.